Decision-making in social systems: injustice, inequality, and ignorance

I present three studies exploring decision-making in artificial social systems that provide insight on the situational factors and individual differences relevant to political engagement. Studies 1 and 2 aimed to provide insight, using a value-expectancy approach, into the dynamics of individual and group opposition to systemically unfair social contexts. Participants were placed in live interactive groups that highlighted a “class difference” between “Elite” and non-Elite participants. Non-Elite participants made incentive-based decisions to support or challenge the system. In Study 1, I found that individuals were more likely to challenge the system when acting in a group compared to when acting alone. This result was accompanied by greater feelings of efficacy when in a group, but only when participants strongly identified with one another. In Study 2, I showed that efforts to challenge the system were undermined by the opportunity to freeride only when the class difference was not emphasised; when the difference between Elites and Non-Elites was salient, participants were no less likely to challenge when freeriding was possible compared to when it was not. In both studies, the availability of coordinating information reduced the relevance of social identity in moderating feelings of efficacy. These findings add to the literature on collective action by experimentally demonstrating when mobilisation is more likely. Study 3 aimed to explore the extent to which individuals are motivated to discover whether their immediate social context is fair or unfair, and what individual difference traits predict these decisions. Participants completed a task in pairs and were subsequently made aware of the possibility they had been paid differently to their partner. Participants could discover whether payments were unfair or remain in ignorance. The results showed that several individual differences were important for this decision. The most compelling was System Justification, which had a complex influence on participants’ comfort not knowing and whether they chose to seek information. Taken together, the thesis contributes empirical data to an understanding of the attitudes and behaviour of constituents of (potentially) unjust social systems

Risk, Courts, and Agencies

Public risks are precisely the risks that have recently captured the attention of the legal community and the world at large, in no small part because they give rise to such novel problems for lawyers and such grave apprehensions among lay people. Public risks have moved the legal system to relax doctrines--regarding, for example, standards of causation and culpability, burdens of proof, sharing of liability--that were designed to deal with the private risks that once dominated the landscape. And public risks have moved lay people to intensify their demands for risk control measures. These developments suggest that public risks are subject to especially harsh treatment, yet such treatment might often be contrary to minimizing the sum of all risk-related costs. If some public risks, whatever their dangers, are in fact safer or otherwise more beneficial than the risks they would displace, then cost minimization requires open-minded efforts to encourage many of the very technological threats that current legal and popular opinion would instead deter. As a consequence, the question of what to do about public risk has become a subject of considerable (and sometimes heated) debate. That debate is our concern throughout all that follows. We begin in Part I with a summary of the contending views in the ongoing argument about public risk, giving particular attention to two important points of contention. The first of these has to do with attitudes. The general public, and to some degree the legal system as well, have a particular aversion to public risk. Is this justified? The second point of contention, intimately related to the first, has to do with institutions, and especially with judicial versus administrative rule. At present, the courts are playing an important part in shaping the legal response to public risk. Is this sensible? According to one powerfully stated outlook--an outlook that runs directly against the grain of prevailing sentiments--the answer to each of the foregoing questions is a firm no. Our actions increase, rather than minimize, risk costs. We worry too much about public risks and not enough about private ones. We control public risks with a haphazard mix of market, judicial, administrative, and legislative measures that too often proceed in the wrong direction, without coordination, and with too little reliance on agencies and too much on courts. The courts especially are said to pander to uninformed and irrational risk attitudes; their decisions show a myopic bias against new technology and in favor of its victims. New or complex technologies are subjected to a degree of scrutiny that riskier but established (often private) risk sources never underwent and could not survive. As a result, we have too much private risk and too little public risk, not more safety but less. Some of the critics advancing this line call for a reduction of the judicial role in risk assessment and management, and for more reliance on administrative agencies. Agencies, they argue, have more expertise, are more objective and rational, can be more attentive to the net effects of technological advance. Courts, they conclude, should defer to them. This is the set of views that we call into question here. After sketching the lines of debate in Part I, we turn in Part II to a prefatory discussion about why risk has to be regulated at all, and under what circumstances. Part III and much of Part IV then address the debate about institutions, taking up courts and agencies in turn. In Part III, we model the litigation process in a way that suggests how courts might well be managing risk much more productively than one would at first suppose. In Part IV, we pursue a similar model to show why agencies might fall far short of what is claimed on their behalf, were the courts to be more deferential. A significant portion of the agency discussion is devoted to attitudes about risk. The question of attitudes has been begged in the legal debate about public risk, yet the topic is of fundamental importance: attitudes about risk--about the meanings of risk--have much to do with choosing or devising the right management institutions. The comparative analysis of courts and agencies in Parts III and IV leads us to conclude that ambitious proposals to increase the scope of agency authority at the expense of judicial scrutiny are remarkably premature. We stop short of saying that the present institutional arrangements are, however imperfect, the best we can hope for given current understanding. We insist, though, that those critics who would alter existing arrangements through sweeping delegations to experts and bureaucrats have utterly failed to carry a reasonable burden of proof. A careful comparative assessment simply raises too many doubts about the wisdom of wholesale abdication to technocratic rule. Part V underscores this conclusion with some speculation about the larger implications of technocracy in a democratic system. Our concerns in this respect lead us to consider an alternative and currently popular view that public risk should be managed through one or another version of participatory democracy. We end up being as skeptical here as we are about technocracy. Obviously, then, we think that much ground has still to be covered before anyone can confidently come forth with ambitious programs for risk assessment and management. As we see it, the public risk debate presently rests at the inside edge of a vast and expanding universe, an unsurprising thing given that risk has only recently been highlighted on social and legal agendas. The entire topic--its attitudinal, institutional, and scientific aspects--is still so shrouded with uncertainty that it is difficult to be confident about anything other than the need for more information and more argument. What we hope to do is move matters forward by bringing into view some considerations that must (but thus far do not) figure in the ongoing debate

Live Streaming with Gossip

Peer-to-peer (P2P) architectures have emerged as a popular paradigm to support the dynamic and scalable nature of distributed systems. This is particularly relevant today, given the tremendous increase in the intensity of information exchanged over the Internet. A P2P system is typically composed of participants that are willing to contribute resources, such as memory or bandwidth, in the execution of a collaborative task providing a benefit to all participants. File sharing is probably the most widely used collaborative task, where each participant wants to receive an individual copy of some file. Users collaborate by sending fragments of the file they have already downloaded to other participants. Sharing files containing multimedia content, files that typically reach the hundreds of megabytes to gigabytes, introduces a number of challenges. Given typical bandwidths of participants of hundreds of kilobits per second to a couple of megabits per second, it is unacceptable to wait until completion of the download before actually being able to use the file as the download represents a non negligible time. From the point of view of the participant, getting the (entire) file as fast as possible is typically not good enough. As one example, Video on Demand (VoD) is a scenario where a participant would like to start previewing the multimedia content (the stream), offered by a source, even though only a fraction of it has been received, and then continue the viewing while the rest of the content is being received. Following the same line of reasoning, new applications have emerged that rely on live streaming: the source does not own a file that it wants to share with others, but shares content as soon as it is produced. In other words, the content to distribute is live, not pre-recorded and stored. Typical examples include the broadcasting of live sports events, conferences or interviews. The gossip paradigm is a type of data dissemination that relies on random communication between participants in a P2P system, sharing similarities with the epidemic dissemination of diseases. An epidemic starts to spread when the source randomly chooses a set of communication partners, of size fanout, and infects them, i.e., it shares a rumor with them. This set of participants, in turn, randomly picks fanout communication partners each and infects them, i.e., share with them the same rumor. This paradigm has many advantages including fast propagation of rumors, a probabilistic guarantee that each rumor reaches all participants, high resilience to churn (i.e., participants that join and leave) and high scalability. Gossip therefore constitutes a candidate of choice for live streaming in large-scale systems. These advantages, however, come at a price. While disseminating data, gossip creates many duplicates of the same rumor and participants usually receive multiple copies of the same rumor. While this is obviously a feature when it comes to guaranteeing good dissemination of the rumor when churn is high, it is a clear disadvantage when spreading large amounts of multimedia data (i.e., ordered and time-critical) to participants with limited resources, namely upload bandwidth in the case of high-bandwidth content dissemination. This thesis therefore investigates if and how the gossip paradigm can be used as a highly effcient communication system for live streaming under the following specific scenarios: (i) where participants can only contribute limited resources, (ii) when these limited resources are heterogeneously distributed among nodes, and (iii) where only a fraction of participants are contributing their fair share of work while others are freeriding. To meet these challenges, this thesis proposes (i) gossip++: a gossip-based protocol especially tailored for live streaming that separates the dissemination of metadata, i.e., the location of the data, and the dissemination of the data itself. By first spreading the location of the content to interested participants, the protocol avoids wasted bandwidth in sending and receiving duplicates of the payload, (ii) HEAP: a fanout adaptation mechanism that enables gossip to adapt participants' contribution with respect to their resources while still preserving its reliability, and (iii) LiFT: a protocol to secure high-bandwidth gossip-based dissemination protocols against freeriders

Behavioral Economics - Enhanced: Machine Learning and Decision Making

In this thesis, I investigate decision-making in the fields of behavioral economics, experimental economics, and law and economics. The research questions I ask are: Can we nudge people towards being more honest? Can we use language to find out who lies? Which factors influence a judge’s decision, and how do people cooperate? Specifically, I investigate contributions in a public goods game, (dis-)honest decision-making in a die-in-the-cup and tax compliance game. Furthermore, I investigate the bounds of rational decision-making in the context of the law. To answer the posed questions, I apply – alongside traditional econometrics – machine learning methods: I use natural language classification to predict decisions based on text data. Furthermore, I use time-series clustering to reduce complexity and thereby enable theory building and interpretation

Risk, Courts, and Agencies

Public risks are precisely the risks that have recently captured the attention of the legal community and the world at large, in no small part because they give rise to such novel problems for lawyers and such grave apprehensions among lay people. Public risks have moved the legal system to relax doctrines--regarding, for example, standards of causation and culpability, burdens of proof, sharing of liability--that were designed to deal with the private risks that once dominated the landscape. And public risks have moved lay people to intensify their demands for risk control measures. These developments suggest that public risks are subject to especially harsh treatment, yet such treatment might often be contrary to minimizing the sum of all risk-related costs. If some public risks, whatever their dangers, are in fact safer or otherwise more beneficial than the risks they would displace, then cost minimization requires open-minded efforts to encourage many of the very technological threats that current legal and popular opinion would instead deter. As a consequence, the question of what to do about public risk has become a subject of considerable (and sometimes heated) debate. That debate is our concern throughout all that follows. We begin in Part I with a summary of the contending views in the ongoing argument about public risk, giving particular attention to two important points of contention. The first of these has to do with attitudes. The general public, and to some degree the legal system as well, have a particular aversion to public risk. Is this justified? The second point of contention, intimately related to the first, has to do with institutions, and especially with judicial versus administrative rule. At present, the courts are playing an important part in shaping the legal response to public risk. Is this sensible? According to one powerfully stated outlook--an outlook that runs directly against the grain of prevailing sentiments--the answer to each of the foregoing questions is a firm no. Our actions increase, rather than minimize, risk costs. We worry too much about public risks and not enough about private ones. We control public risks with a haphazard mix of market, judicial, administrative, and legislative measures that too often proceed in the wrong direction, without coordination, and with too little reliance on agencies and too much on courts. The courts especially are said to pander to uninformed and irrational risk attitudes; their decisions show a myopic bias against new technology and in favor of its victims. New or complex technologies are subjected to a degree of scrutiny that riskier but established (often private) risk sources never underwent and could not survive. As a result, we have too much private risk and too little public risk, not more safety but less. Some of the critics advancing this line call for a reduction of the judicial role in risk assessment and management, and for more reliance on administrative agencies. Agencies, they argue, have more expertise, are more objective and rational, can be more attentive to the net effects of technological advance. Courts, they conclude, should defer to them. This is the set of views that we call into question here. After sketching the lines of debate in Part I, we turn in Part II to a prefatory discussion about why risk has to be regulated at all, and under what circumstances. Part III and much of Part IV then address the debate about institutions, taking up courts and agencies in turn. In Part III, we model the litigation process in a way that suggests how courts might well be managing risk much more productively than one would at first suppose. In Part IV, we pursue a similar model to show why agencies might fall far short of what is claimed on their behalf, were the courts to be more deferential. A significant portion of the agency discussion is devoted to attitudes about risk. The question of attitudes has been begged in the legal debate about public risk, yet the topic is of fundamental importance: attitudes about risk--about the meanings of risk--have much to do with choosing or devising the right management institutions. The comparative analysis of courts and agencies in Parts III and IV leads us to conclude that ambitious proposals to increase the scope of agency authority at the expense of judicial scrutiny are remarkably premature. We stop short of saying that the present institutional arrangements are, however imperfect, the best we can hope for given current understanding. We insist, though, that those critics who would alter existing arrangements through sweeping delegations to experts and bureaucrats have utterly failed to carry a reasonable burden of proof. A careful comparative assessment simply raises too many doubts about the wisdom of wholesale abdication to technocratic rule. Part V underscores this conclusion with some speculation about the larger implications of technocracy in a democratic system. Our concerns in this respect lead us to consider an alternative and currently popular view that public risk should be managed through one or another version of participatory democracy. We end up being as skeptical here as we are about technocracy. Obviously, then, we think that much ground has still to be covered before anyone can confidently come forth with ambitious programs for risk assessment and management. As we see it, the public risk debate presently rests at the inside edge of a vast and expanding universe, an unsurprising thing given that risk has only recently been highlighted on social and legal agendas. The entire topic--its attitudinal, institutional, and scientific aspects--is still so shrouded with uncertainty that it is difficult to be confident about anything other than the need for more information and more argument. What we hope to do is move matters forward by bringing into view some considerations that must (but thus far do not) figure in the ongoing debate

Recreation, tourism and nature in a changing world : proceedings of the fifth international conference on monitoring and management of visitor flows in recreational and protected areas : Wageningen, the Netherlands, May 30-June 3, 2010

Proceedings of the fifth international conference on monitoring and management of visitor flows in recreational and protected areas : Wageningen, the Netherlands, May 30-June 3, 201

Three Essays on Defending Common-Pool Resources

% !TEX root = ../degeest2017dissertation.tex Environmental protection often relies on cooperation between individuals in uncoordinated groups. In cases such as the management of common-pool resources, individuals must not only monitor and enforce behavior within their group to prevent over-exploitation. They must also contend with external threats on the resource like poaching. This dissertation studies how individuals cooperate to manage shared resources and deter shared threats. The first chapter, Deterring poaching of a common-pool resource , considers the problem of deterring a threat that cannot be perfectly observed. I present results from common pool resource experiments designed to examine the ability of a group of resource users, called insiders, to simultaneously manage their own exploitation and defend their resource from encroachment by outsiders. The insiders can use communication, peer monitoring and sanctions to coordinate their decisions. In addition, they can sanction any outsiders they observe. I vary the insiders\u27 ability to observe and sanction the outsiders from no observability to partial and full observability. I find a striking non-monotonicity between observability of the outsiders and levels of poaching. Poaching was higher under partial monitoring than zero monitoring, and was lower and more stable under full monitoring. Although full observability allowed the insiders to better coordinate their own harvests, they were unable to fully deter poaching because their sanctions were far too low and they were unwilling to punish low levels of poaching. The second chapter, Defending public goods and common-pool resources , studies cooperation and deterrence of a shared threat in different strategic environments. In many real-world social dilemmas, groups of individuals must cooperate to create surplus and defend it from theft. Theft can either foster or discourage collective action. On the one hand, a shared threat can align individual incentives. On the other hand, surplus creation may decrease if individuals are unsure how group members will contribute towards defense. Moreover, there is literature that suggests cooperation is sensitive to whether individual actions confer positive externalities (public goods, PG) or negative externalities (common-pool resources, CPR) on group members -- the cooperation divergence . To examine the relationship between cooperation and defense in different externality settings, I conduct an experiment in which a group of insiders providing a public good or conserving a common-pool resource must coordinate to deter outsiders from stealing the value of their surplus. Our theory predicts that theft will have no different effect on behavior across externality settings. However, I find that it does. Surplus creation is significantly higher in the CPR treatment, while surplus defense is significantly higher in the PG treatment. Across both treatments, I find that the shared threat increases variation within groups, but the effect is more dramatic in the PG treatment. Finally, the third chaper, Enforcement networks in social dilemmas , studies how enforcement emerges and evolves in the first chapter. Sanctions can increase cooperation in social dilemmas, but they impose a high social cost until a credible threat to non-cooperative behavior is established. Moreover, credible threats depend on enforcement structure. For example, small sanctions implemented by many subjects may have a different impact on behavior than the same volume of sanctions meted out by a single subject. In order to understand how credible threats to deviant behavior emerge, it is therefore necessary to study how enforcement structure emerges and evolves in groups. I study enforcement structure by taking a network approach to data from a social dilemma experiment with peer punishment. The exchange of sanctions between subjects can be framed as a directed, weighted network that evolves, enabling us to use tools from network structure to summarize, predict and simulate behavior. I first visualize and summarize the structure of these networks and show that enforcement structure is non-random and tends to cluster around a few individuals. I then model network formation and network efficiency using an empirical framework that separately considers edge formation (a binary sanctioning event) from edge weight (sanction size) and find that subjects respond more to the act of being sanctioned rather than the volume of sanctions. Finally, I recover the underlying Markov process governing enforcement structure and simulate expected long-run behavior. I conclude with a discussion of how my approach can be used to study generalized exchange networks